Electric illumination



March 26, 1935. K. F. J. KlRsTEN 1,995,512

ELECTRIC ILLUMINATION Filed Deo. .1, 1930 FIGA i VENTOR f v Patented Mar.26, 1935 I f. Y

UNITED i STATES `PATEN'r olfncl?.

ELECTRIC ILLUMINATION Kurt F. J. Kirsten, seattle, wesh., assigner to Kirsten Lighting Corporation, a corporation ofvWashington A Application December 1, 1930, lserial No. 499,253

" sclsims. (cl. 176-122) In the art of electric illumination, gas-lled these, thegas neon may be mentioned as an extubes in which ionization, arcing, and consequent ample. 1 l illumination are eil'ected have been used in many What my invention comprises is set forth in applications. In nearly all apparatus of this the following speciication and succinctly defined 5 kind the gas-arc tube is very long in proportion in the appended claims.

to its diameter, and the excitation voltage is of. Referring to the accompanying drawing: the ordrr of several thousand volts. In a few Figure 1 shows certain elements of my inven instances, very small gas-arc lamps have been tion in a. limited embodiment;

used for voltages or the order of 120 for indicat- Figure 2 shows my invention in its present preing purposes, `but, as their capacity is usually felled forni; l0 very small, these have not been used as sources Figure 3 iS a SeCtiOnal VieW 0f Dart Of the eleof light suitable for any large scale illumination. ments ShOWn in Figure 2; and

In any gas-arc lamp in which there is no con.. Figure 4 isa group ofcurves which assist in ducting liquid, the luminous arc is started by the eXplanatiOn f my invention l5 the introduction of a potential gradient at or In my inveniiOll, the ebOVe mentioned lilniiu- 15 between a pair of electrodes in the gas, This tions of the simple low voltage gas-arc lamps potential gradient causes ionization of the gas have been Overcome by the uSe'Of a lamp 0f the and causes an arc to exist between the eleckind Shown in Figure 1. In Figure 1, tWO electrodes. In the ordinary gas-arc lamp used for' trodes 1 and 2, of novel form, are sealed into a' sign lighting and other purposes, the distance glass tube or other transparent insulating en- 20 between the electrodes is of the order of one VelODe 3 containing gas 4. The electrodes 1 and meter or more, and the potential is several thou- 2 are provided with terminals 5 and 6,r respecsand volts. I1 the tube is shortened so the distively. brought out of the tube in any convenient tance between the electrodes is only a few millimanner, Voltage is applied to'terminols 5 and 6 meters, the arc may be started with a voltage from any convenient source of energy of suitable as iow as about 125 volts. 1f simple e1eetrodes characteristics The electrodes 1 and 2 are are-used, the energy that can be accommodated `helices or. coils of wire terminating in adjacent by the 1amp is extremelysmall and of little use ends 7 and 8. The'ends 'l and 8 ofthe coils 1 and in illumination, The gasarc lamps mentioned 2 are spaced a few millimeters apart. When the abuve generally use single nhase alternating character and pressure of the gas in the tube are 30 Cun-ent suitable, for example neon at between ten and twenty millimeters of mercury pressure, an arc Mgg: fgsllgbggagfisholnt 11g gas-arc vcan be started between the electrode ends 7 and addition 8 at about 125 volts. By increasing the voltage. to the .advantages of the high voltage gas-faro t 35 o about 160 volts, the electrodes are caused to lamp among whlch may be mentioned those of be surrounded entirely by a luminous arc The long life and low intrinsic brillian cy, the low arc is caused to be distributed evenly along the voltage lamp can have the advantages 016918175" electrodes by an adjustment of the voltage gradifreedom Imm step'm Whse trnsmfmefs inent from the ends 7 and a of the electrodes 1 4 creased luminosity for s given amountef meteand 2 to the terminals 5 ena s, such that the 40 rial, and the feasibility 0f c0nt1'0llln8 the size and voltage diierence between ends 'l and 8 of the light output of the lamps between greater electrodes 1 and 2 to the terminals 5 and 6 -is IAlso, by moldns use of Suitable sesos end other. just sumcient to overcome the increase of imelements such .Bs mercury in lamps enclsed nl pedance due to the longer arc path. This voltage glass transparent t0 ultra-Violet light the 10W gradient is controlled by the design of the elec- 4voltaire lamp is available for domestic and other trodes, whiensre mede with sumeientimpedsnce uses where ultra-violet radiation is required. to aecompush' the result desired, MY invention T elates t0 Sas'afc lamps 0f 10W If the voltage applied to the lamp is unidirec- 50 voltage. which may be developed for high lllumltional. the negative electrode win glow, but vthe niing Wettg- In C0nlln0n with OtherSS-are positive one will remain dark. If the applied lamps', my illYentiOll USBS the SO-eelled I'l'e gases voltage is alternating, it can be demonstrated by which can be caused to -be conducting, or, as it oscillographic observation that first one electrode isusually expressed, ionized and hence luminous and then the other glows in synchronism with 55 with a Vminimum expenditure of energy. Among the applied voltage. It can be shown also that 55 I nary three-phase relationship.

' assume represents the alternating voltage applied to the lamp shown in Figure 1, doubly hatched areas 14 represent the current that flows. 'Ihe areas 14 above the axis 10 represent the current flowing when the gas at electrode 1 is luminous,

and the areas 14 below the axis 10 represent the current flowing when the gas at electrode 2 is luminous. The resultant effect is av discontinuous and shifting light with appreciable flicker.

In order to overcome the objection of discontinuous light emission of the lamp shown in Fig-- ure 1, I havefinvented a lamp of the form shown in Figures 2 and 3. In Figures 2 and 3, there are a plurality of electrodes 21, 22, and 23, contained in a glass or other transparent insulating sealed envelope 24, through whose walls current is conducted from terminals 25, 26, and 27. Gas 28 of suitable characteristics and pressure is also contained in the envelope 24. The electrodes 21, 22, and 23 are supported, when necessary, by an insulated support 29. The electrodes 21, 22, and 23 terminate in an insulating holder 30, at which the ends 31,32, and 33 of the electrodes 2l, 22, and

23 are held a few millimeters apart. 'Ihe arrangement of the electrodes in plan in the lamp is shown in Figure 3, which is a sectional view through Figure 2 at the points X-X in the direction indicated by the arrows.

In operation, the lamp shown in Figures 2 and 3 is connected by means of the terminals 25, 26,

and 27 to any suitable source of three-phase alternating current. A voltage of about 105 volts between each of the terminals 25,26, and 27 is sucient to start arcing in the gas at the en ds 31, 32, and 33 .of the electrodes 21, 22, and 23. With `somewhat greater voltage the gas surrounding all three of the electrodes becomes luminous. The proportions and shapes of the electrodes and the space's between them are designed so that the increase of voltage between the ends 3l, 32, and 33 of the electrodes 21, 22, and 23 where the current is a to the other ends of the electrodes 2l, 22, and 23, where the current is a maximum, is graded so that the intensity of illumination of the gas between the electrodes is substantially uniform throughout the length of the electrodes.

Referring again to Figure 4,i the comparative performances of the lamps illustrated in Figures 1 and 2 will be explained. It was pointed out that the illumination produced by the lamp shown in Figure l, which is operated on single-phase current, was periodic and discontinuous, as was illustrated by the doubly hatched areas. With reference to Figure 2,'the curves ll, 12, and 13 in Figure 4 represent the voltages between the terminals 25 and 26, 26 and, 27, and 25 and 27 respectively, and the singly hatched areasl represent the currents caused to flow by these voltages. Since the light produced is more or less proportional to the current flowing, the singly hatched areas 15 also represent light produced.

Figure 4 that currents ilow between the respective electrodes 21, 22, and 23 of Figure 2 discontinuously, as between the electrodes l and 2 in Figure 1, but that the presence .of a third electrode permits some current to flow all the time, since the impulses of current overlap. The result is continuous ionization of the gas in the lamp. Since the gas is ionized continuously. it is not necessary tn reestablish the arc each half cycle as in the lamp shown in Figure 1, and therefore the lamp will operate at a lower voltage than one which has to be continually reionized. Also light is emitted continuously so there is no icker.

'I'he curves in Figure 4 are not intended to show quantitative relationships of voltages and currents with any degree of accuracy, but are intended merely to illustrate the nature of the phenomena encountered.

Likewise, it should be understood that the use of three-phase voltage and current in this instance is assumed for purposes of explanation only, and that any multi-phase alternating current system may be used, suchas two, three, four, or six phase systems.

In Figure 2 the electrodes 21, 22, and 23 are shown partly straight andpartly coiled. The relative amounts of the straight and coiled portions can be varied to suit conditions, and they may be either coiled over practically the entire length or not coiled at all. Ordinarily the resistances of the electrodes 2l, 22, and 23 are not sumciently high to cause them to be heated appreciably, and therefore the light emitted by the lamp ordinarily is that produced by the gaseous arc. However, if it be desirable, the resistances of the electrodes can be of such values that the currents owing therein will heat them to incandescence` so that light is produced by both the gas in the tube and the heated electrodes.

In certain embodiments of my invention the elec-y trodes are self-supporting, making the support 29 unnecessary.

I claim:

1. An electric lamp comprising a sealed transparent envelope containing gas, a plurality of electrodes arranged symmetrically in said envelope, and held in position by a suitable insulated support, lsaid electrodes being vspaced so that when alternating multi-phase voltages of the order of 100 volts are applied thereto, current ow and arcing will take place in said gas, said current ow and arcing in said gas being distributed them increase toward the ends where they enter through said walls of said envelope, and said elecf trodes having impedances appreciable in comparison with the impedance of the gasvbetween them when said three-phase currents are owing.

3. A multi-phase alternating current electric lamp comprising a transparent sealed envelope containing gas and a plurality of electrodes arranged to receive multi-phase current through the walls of said envelope, 'said electrodes arrents are flowing.

' 4. The method of produlng light electrically which consists of causing multi-phase currents to ow between elongated uniform metallic resistors in a. volume of gas in arc paths of various lengths in which the voltages impressed on said paths have graded lvalues corresponding' to their lengths.

5. An electric lamp comprising a sealed transparent insulating envelope containing an ionizable ses, terminals sealed in the envelope on which electrical potential may be impressed, elec. trodes in the envelope with ends connected to the vterminals and other ends directedtoward each other and terminating in spaced relation; each electrode being a uniform metallic resistor from end to end and of such impedance as to cause current to flow between the electrodes in paths of various lengths in which the voltages impressed have graded values corresponding to the lengths of the paths.

6. A multi-phase gas are lamp comprising a sealed, transparent envelope containing an ionizable gas, aplurality of insulated electrodes arranged in the envelope to receive andtransmit alternating currents; said electrodes being symmetrieally arranged and each an elongated, uniform metallic resistor designed to effect an adjustlnent of voltage gradient therealong whereby current will ilow between the said electrodes in are paths of various lengths.

'1. A gas are electric lamp-comprising a sealed. transparent envelope containing an ionizable gas.

elonsald electrodes in diverging relationship.,

connected at their outer ends with a source of current and arranged in said envelope with their opposite ends closely spaced to permit arcing between them at low voltages; saidelectrodes being uniform, metallic resistors thereby to 'effect a voltage gradient therealong whereby ciment will be caused to ilow between them throughout their lengths in arcs of various lengths in which the voltages impressed have graded values corresponding to the lengths of the paths.

8. An electric lamp comprising a sealed, transparent envelope containing an ionizable gas, electrodes of coiled formation arranged in said envelope in co-axial alinement with their inner ends closely spaced to permit arcing therebetween at low voltage and with circuit connections at their outer ends:` said electrodes being uniform in material and resistance throughout their lengths to eil'ect a voltage gradient from end to end whereby the arc will be progressively distributed therealong.

KURT l". J. KIRSTEN. 

